Description

There is a use of 'xrange' in the In lookup class in django/db/models/lookups.py, within the "list too long for db backend" case. "xrange" is not present on Python 3, so this code will fail there.

The fact that tests are passing on both Python 2 and 3 suggests that this code branch is untested, and I confirmed by inserting a pdb.set_trace() at that point and running the full test suite. That's a sizable code branch; it should be tested.